Fabric and method of making same



Patented Jan. 2, 1940 PATENT OFFICE FABRIC AND METHOD OF MAKING SAMECyril M. Croft, Cumberland, Md., assignor to Celaneae Corporation ofAmerica, a corporation of Delaware No Drawing. Application July 24,1937,

a Serial No. 155,574

'11 Claims.

This invention relates to crepe fabrics that contain a substantialamount of threads of an organic derivative of cellulose and to themethod of making the same. The invention relates particularly to theprocess of making crepe satins of all cellulose acetate yarns which arenot delustered.

An object of the invention is the economic and expeditious production ofcrepe fabrics containing yarns of an organic derivative of cellulose,which fabric has the full luster of uncreped fabrics containing yarns ofan organic derivative of cellulose. Another objectof the invention isthe production of an all cellulose acetate crepe satin that has a fullluster. Other objects of the invention will appear from the followingdetailed description.

It is known that crepe fabrics may be produced from highly twistedthreads of an organic derivative of cellulose, the twist being insertedin the threads in the presence of steam, hot water, water vapor,plasticizers or other softening agents.

These highly twisted threads containing an organic derivative ofcellulose are woven into a fabric and, with or without embossing and/ordelineating a pattern thereon, are treated in a bath at or near theboiling temperature to effect a shrinkage and creping of the fabric.Fabrics produced by said method, wherein they are subjected to treatingbaths at or near the boil, are delustered to some extent and, as in thecase of crepe satins, to an appreciable extent. By employing the presentinvention, fabrics made in the usual manner may be processed to raisethe crepe pebble thereon without producing a visible delustering effect.

I have found that crepe fabrics made of yarns containing an organicderivative of cellulose and woven in the same way as the fabricscontaining similar yarns may be shrunk to form the pebble or crepeeffect, without any visible delustering by entering the fabric in acreping bath that is below the temperature of that required to producecommercially a crepe and then raising the temperature of the bath highenough to produce a crepe effect but below the boiling point of thebath. Although the maximum temperature will vary according to thecomposition of the bath and the time of treatment, according tothe broadprinciple of his invention the maximum temperature may be substantiallyatbut below the boiling point of the creping bath.

In accordance with myinventioii, I produce crepe fabrics, and especiallycrepe 'satins that contain a substantial amount of filaments or fibresof an organic derivative of cellulose and that have a full luster, byfabricating highly twisted yarns to a fabric, entering the fabric in acreping bath that is below a rapid or commer cial creping temperatureand then raising the temperature to a maximum that is from 6 to 1 C.below the boiling point of the bath and preferably from to 3 C. belowsaid boiling point. By a rapid or commercial creping temperature as usedabove is meant a temperature at which a substantial amount of crepeeffect is produced in the fabric on immersion of the fabric in the bathfor an hour. The length of time for bring-- ing the bath and the fabricfrom the lower temperature up to the maximum temperature may varyaccording to the bulk of the fabric, the type of fabric being creped,and the composition of the treating bath. The most satisfactory resultsare obtained if this time interval is atleast minutes for every 5 C.rise in temperature, and preferably minutes for every 5 C. rise. lengthof time the fabric and the bath are held -at the maximum temperaturewill depend upon the degree of crepe desired, whether the fabric has hada prior embossing or delineating treatment and the maximum temperatureof the bath. The higher the temperature of the bath the shorter will bethe period required When the fabric has been embossed or has had a crepepattern thereon a shorter period of treatment of the fabric at themaximum temperature is required. This period of'maximum temperature maybe from 10 minutes to an hour or more, but preferably around 15 tominutes for an all cellulose acetate crepe satin when the bath is plainwater- The I baths are obviously preferred for commercial reasons,enhanced results may be obtained by maintaining the pH value of the bathat between 5.5 to 6.- The control of the pH value of the bath may beeffected by the'addition to the bath-of what is known as protectivesalts such as sodium sulphate, sodium citrate, etc. -By maintaining thepH value between-the above limits a minimum delustering action isproduced at ,a given temperature. Therefore, when employing a protectivesalt as a control for the pH value, the

temperature of the treating bath may be raised nearer the boiling pointof the bath, which boiling point will be higher than a plain water bath,

This invention is applicable to the production of fabrics produced fromor containing crepe yarns of organic derivatives of cellulose such asorganic esters of cellulose 'and the cellulose ethers. Examples oforganic esters of cellulose are cellulose acetate, cellulose formate,cellulose propionate and celluose butyrate, while examples of celluloseethers are ethyl cellulose, methyl cellulose and benzyl cellulose. Theyarns may contain the organic derivative of cellulose in the form ofsubstantially continuous filaments twisted together, short lengths offilaments spun together, or relatively long discontinuous lengths offilaments so twisted that they appear in the yarn as a staple fibre.

Fabric to be processed in accordance with this invention may be woven inany suitable manner and from any suitable yarns, some of which containorganic derivatives of cellulose. The fabric may be woven from single ordoubled yarns or threads or combinations of these. Thus there may beused threads of organic derivatives of cellulose that are formed bydoubling a thread of high twist and a thread of low twist or two threadsof uniformly high twist. Crepe yarns containing organic derivatives ofcellulose may be twisted to their high degree of twist say from 40 to100 turns or more per inch in one or two stages with or without sizes,resins, gums, etc. Yarns containing an organic derivative of cellulosethat have a high degree of twist and that have been treated byprecipitating lead sulphate in the threads may be employed. Moreover,the threads before twisting may be treated with materials such asferrocyanide, thiosulphates, citrates, lactates, etc., or the threadsmay be pretreated before twisting with a latent solvent such aschloroform, tetrachlorethane, ethyl acetate, etc., or the threads may betreated before twist ing with hot water, steam, solvent vapors, etc.

with or without stretching. Although any method of imparting a twist tothe yarns may be employed, it is preferable to twist the threadcontaining an organic derivative of cellulose, or at least insert partof the twist in the thread, in the presence of steam, hot water, watervapor, or other softening agents in the vapor or liquid state. Theseagents, such as the steam, hot water or water vapor, may be applied tothe yarn either immediately before twisting, during twisting, during onestage of the twisting or immediately after twisting.

The crepe threads, that is threads containing a high degree of twist,formed of an organic derivative of cellulose may be doubled withthreads, for instance those having a twist of from 40 or more tums perinch and made of the same material, or with threads of such twist formedof reconstituted or regenerated cellulose, cotton, silk, wool, etc. Thecrepe yarns of an organic derivative of cellulose may also be doubledwith threads formed of organic esters of cellulose that have beencontinuously saponi fied, partially saponified or'intermittently orperiodically saponified. Also, the crepe yarns or threads containingorganic esters of cellulose may be partially or intermittentlysaponifled after their formation into the crepe threads.

These threads and yarns may be woven into a fabric in any suitablemanner. The yarns and threads containing organic derivatives ofcellulose may be woven alternatively with yarns or threads of othermaterials such as silk, cotton, etc. The crepe yarns containing organicderivatives of cellulose may also be employed for the raised to 95 C. in15, minutes.

weft or warp. For large pebble effects the fabric may be formed fromthreads having three or more ends of righthand twist alternating withone or more ends of left hand twist or vice-versa. Fine pebble crepefabric may be produced by laying either in the warp or weft, or both,one yarn of righthand twist and one yarn of left hand twist. Anyarrangement of weave and sequence of yarns or threads may be employed.The invention, however, is particularly applicable to the production offabrics having fioats'of noncreping yarns on one side and interwovencrepe yarns on the other side, producing fabric known as crepe satin.The invention is especially of importance in the production of crepesatins in which all the yarns are substantially formed of celluloseacetate. In this type of fabric it is often desirous to have a fullluster of the natural cellulose acetate yarns. This full luster isdiminished in the creping treatments as heretofore practiced and it wasnecessary to obtain the full luster by treating the fabric withrelustering agents which meant an additional and expensive treatment.Moreover, there was always the danger of lowering the grade of thefabric due to the extra treatment in heated baths as well as thepossibility that the treatment if not carefully controlled would greatlyweaken the fabric. In accordance with this invention, the fabricmaintains its full luster during the creping treatment and is notsubjected to chemicals which might be injurious to the fabric if notunder the supervision of experts.

The creping treatment, as stated above, is preferably effected in bathsof plain water. The fabric should enter the bath while the same ismaintained at below C. and the temperature gradually raised to betweenand 98 0. Temperatures, however, will vary from those herein given whenprotective salts are added to the bath. Instead of a batch process, theinvention may be carried out in a continuous method by entering thefabric into a bath at a temperature below the commercial crepingtemperature, drawing the fabric from this bath to a succeeding bath atslightly higher temperature and then to a bath of maximum temperaturewhere it is retained for a sufficient length of time to produce thecrepe effect desired, and then removed and dried. In a continuous method2, 3, 4 or more baths may be employed. In such a method it is foundpreferable to treat the fabric in hank form thereby mai taining thetension on both warp and weft a a minimum. In place of the series ofbaths as above desired, there may be employed one bath wherein theheated treating liquid enters one end counter-current to the fabric andis cooled as it nears the other end where the fabric enters the bath.Employing a single tank with suitable baiiles, the temperature of thebath at one end of the tank may vary a suitable number of degrees fromthe temperature of the bath at the other end.

In order to further illustrate my invention without being limitedthereto, the following example is given:

Example An all cellulose acetate crepe satin having crepe thread fillingis entered in hank form in a plain water bath at 90 C. and the bath andthe fabric The fabric is allowed to remain in the bath for another 15minutes at the maximum temperature and then withdrawn from the bath and.dried. The fabric 15 is sufficiently shrunk to give a pleasing crepeeffect on the one side without diminishing appreciably the luster on thesatin side of the fabric.

It is to be understood that the foregoing detailed description is merelygiven by way of illustration and that many variations may be madetherein without departing from the spirit of my invention.

Having described 'my invention, to secure by Letters Patent is:

1. Process for the production of crepe effects on fabrics containinghighly twisted yarns at least some of which contain organic derivativesof cellulose, which comprises entering the fabric into a treating bathwhich is at a temperature below 90 C. and gradually raising the bathcontaining the fabric to a temperature near but below the boiling pointof the bath.

2. Processfor the production of crepe effects on fabrics containinghighly twisted yarns at least some of which contain cellulose acetate,which comprises entering the fabric into a treating bath which is at atemperature below 90 C.

and gradually raising the bath containing the fabric to a temperaturenear but below the boiling point of the bath.

3. Process for the production of crepe effects on fabrics containinghighly twisted yarns at least some of which contain organic derivativesof cellulose, which comprises entering the fabric into a treating bathof plain water which is at a temperature below 90 C. and graduallyraising the bath containing the fabric to a temperature near but belowthe boiling point of the bath.

4. Process for the production of crepe effects on fabrics containinghighly twisted yarns at least some of which contain cellulose acetate,which comprises entering the fabric into a treating bath of plain waterwhich is at a'temperature below 90 C. and gradually raising the bathcontaining the fabric to a temperature near but below the boiling pointof the bath.

5. Process for the production of crepe effects on fabrics containinghighly twisted yarns at least some of which contain organic derivativesof cellulose, which comprises entering the fabric into a treating bathof plain water which is at a temperature below 90 C. and graduallyraising the bath containing the fabric at a rate less than 1 C. perminute to a temperature near but .below the boiling point of the bath.

6. Process for the production of crepe effects on fabrics containinghighly twisted yarns at 55 least some of which contain celluloseacetate,

10 what I desire which comprises entering the fabric into a treatingbath of plain water which is at a temperature below C. and graduallyraising the bath containing the fabric at a rate less than 1 C. perminute to a temperature near but; below the boiling point of the bath.

'7. Process for the production of crepe effects on fabricscontaininghighly twisted yarns at least some of which contain organicderivatives of cellulose, which comprises entering the fabric into atreating bath of plain water which is at a temperature below 90 0.,raising the bath containing the fabric to between and 98 C. in 15minutes and maintaining the bath at this temperature for a further 15minutes.

8. Process for the production of crepe effects on fabrics containinghighly twisted yarns at least some of which contain cellulose acetate,which comprises entering the fabric into a treating bath of plain waterwhich is at a temperature below 90 C., raising the bath containing thefabric to between 95 and 98 C. in 15 minutes and maintaining the bath atthis temperature for a further 15 minutes.

9. Process for the production of crepe satin effects on fabricsconsisting of organic derivatives of cellulose and having floats ofnon-creping yarns on the one side and interwoven high twist yarns on theother side, which comprises entering the fabric into a treating bathwhich is at a temperature below 90 C. and gradually raising the bathcontaining the fabric to a temperature near but below the boiling pointof the bath.

10. Process for the production of crepe satin effects on fabricsconsisting of cellulose acetate and having floats of non-creping yarnson the one side and interwoven high twist yarns on the other side, whichcomprises entering the fabric into a treating bath which is at atemperature below 90 C. and gradually raising the bath con-- minutes andmaintaining the bath at this temperature for a further 15 minutes.

CYRIL M. CROFI'.

